Research On Attitude Control Of Quadrotor UAV Based On Super-twisting Algorithm

The quadrotor UAV has great application fields and broad development prospects due to its small size,strong maneuverability and easy maintenance,and has always been the focus of research at home and abroad.However,the quadrotor UAV is a typical underactuated system that is affected by nonlinear,strong coupling and uncertainties,and the design of its robust and highly reliable controller faces challenges.In order to improve the performance of attitude controller of the quadrotor UAV,this paper focuses on the attitude control method of the quadrotor UAV based on super-twisting sliding mode.The main research contents include:Firstly,considering the influence of uncertain disturbance boundary unknown on the attitude control performance of quadrotor UAV,an adaptive multivariable supertwisting sliding mode attitude control method with non-overestimation characteristics is proposed.The method is based on the equivalent control to design the nonoverestimated adaptive gain,for ensuring the control gain adaptively adjusts with external disturbances,and further combines the super-twisting control algorithm to design an adaptive multivariable super-twisting attitude controller.Based on Lyapunov technology,the sufficient conditions for the stability of the system is deduced,and realizing the stable tracking control of the reference command by the quadrotor UAV in a limited time while achieving effective suppression of external disturbances.Secondly,considering the influence of uncertain interference and limited computing power on the attitude control performance of quadrotor UAV,an eventtriggered super-twisting sliding mode attitude controller design method is proposed.In this method,the triggering condition for making the closed-loop system stable are derived based on Lyapunov theory.On this basis,the free-Zeno phenomenon of the triggering time sequence is ensured,which enables the quadrotor UAV to reduce the number of updates of controller while ensuring the performance of the control system,and achieve stable attitude tracking control while saving computing resources.Finally,an adaptive event-triggered super-twisting attitude control algorithm is designed to solve the problem that the parameters of the above event-triggered supertwisting controller depend on the boundary of disturbances.The adaptive gain design of this method does not need to know any information about the boundary of disturbances and has the characteristics of non-overestimation.Furthermore,combining with event-triggered super-twisting control algorithm,an adaptive event-triggered super-twisting sliding mode attitude controller is designed.The stability of the closedloop system is proved by Lyapunov method and it is proved that the Zeno phenomenon does not occur in the triggering sequence.It ensures that the quadrotor UAV can achieve stable attitude tracking when the boundary of disturbance is unknown,and ensures the control performance while reducing the computational cost.